α-Synuclein aggregates amplified from patient-derived Lewy bodies recapitulate Lewy body diseases in mice

Extraction of α-Synuclein (αSyn) aggregates from Lewy body disease (LBD) brains has been widely described yet templated fibrillization of LB-αSyn often fails to propagate its structural and functional properties. We recently demonstrated that aggregates amplified from LB-αSyn (ampLB) show distinct biological activities in vitro compared to human αSyn preformed fibrils (hPFF) formed de novo. Here we compare the in vivo biological activities of hPFF and ampLB regarding seeding activity, latency in inducing pathology, distribution of pathology, inclusion morphology, and cell-type preference. Injection of ampLB into mice expressing only human αSyn (male Thy1:SNCA/Snca–/– mice) induced pathologies similar to those of LBD subjects that were distinct from those induced by hPFF-injection or developing spontaneously with aging. Importantly, αSyn aggregates in ampLB-injected Thy1:SNCA/Snca–/– mice maintained the unique biological and conformational features of original LB-αSyn. These results indicate that ampLB-injection, rather than conventional PFF-injection or αSyn overexpression, faithfully models key aspects of LBD.

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Data analysis
For manuscripts utilizing custom algorithms or or software that are central to to the research but not yet described in published literature, software must be be made available to to editors and reviewers.We We strongly encourage code deposition in in a community repository (e.Note that full information on on the approval of of the study protocol must also be be provided in in the manuscript. et et al., Neuron. 2000).
This study did not include any wild animals.
The major findings in in this study can apply to to both sexes.Sex was considered in in the study design, and we we used only male Thy1:SNCA/ Snca-/-mice because the transgene was inserted in in the X chromosome (Rockenstein E et et al., J Neurosci Res. 2002).Sex-based analyses were not performed because this study did not focus on on sex differences in in LBDs.
This study did not include any samples collected from the field.
All animal procedures were approved by by the University of of Pennsylvania Institutional Animal Care and Use Committee and conformed to to the National Institute of of Health Guide for Care and Use of of Laboratory Animals.
g. GitHub).See the Nature Portfolio guidelines for submitting code & software for further information.Norihito Uemura, Virginia M.-Y. Lee Oct 17, 2023 Image Studio was used to to collect western blot data.IN IN Cell Analyzer 2200 software was used to to image stained primary neurons.Molecular Devices Spectramax M5 M5 plate reader software was used to to read ELISA and BCA assay plates.Pannoramic 250 software was used to to collect immunohistochemical images.Eclipse Ni Ni microscope and TCS SP8 WLL Confocal with STED 3X 3X software was used to to collect immunofluorescent images.EthoVision XT XT 15 15 and fear conditioning test device software were used to to collect behavioral data.ImageJ was used to to quantify western blot data.IN IN Cell Analyzer 2200 software was used to to analyze primary neuron images.Cell Profiler was used to to quantify staining area in in primary neurons.QuPath was used to to quantify staining area in in immunohistochemical images.GraphPad Prism 7 or or 9 was used to to generate standard curves and for statistical analysis.